Method and apparatus for processing photographic prints

ABSTRACT

This disclosure relates to a method and apparatus for processing photographic prints which embodies a mechanism for quickly and easily varying the time of submersion of the paper in the individual developer solution tanks and which permits substantially uniform tensioning of the paper by providing means for automatically adjusting the drive friction between the paper and the driving rollers.

[ 51 June 25, 1972 [54] METHOD AND APPARATUS FOR PROCESSING PHOTOGRAPHIC PRINTS [72] Inventors: Norman C. Reid, Minneapolis, Minn.;

Pako Corporation, Minneapolis, Minn.

221 Filed: June6,l969

[21] Appl.No.: 831,022

[52] US. Cl. ..95/94 R, 95/89 R [51] Int. Cl. ..G03d 3/12 [58] Field of Search ..95/89, 89 A, 94; 1 18/419, 429; 226/170; 134/7 S; 68/5 [56] References Cited UNITED STATES PATENTS 1,351,834 9/1920 Capstaff ..95/94 1,890,026 12/1932 Barkelew... .....95/94 1,967,889 7/1934 Kitroser ..95/94 2,342,780 2/1944 Zollinger ,95/94 2,727,378 12/1955 Cook ..68/5

2,770.179 11/1956 Dye et a1 ..95/94 2,786,736 3/1957 Roughsedge... 95/94 X 3,195,438 7/1965 Woodcock... ..95/94 3,382,790 5/1968 Matheson ..95/94 3,521,544 7/1970 Good ..95/89 X FOREIGN PATENTS OR APPLICATIONS 922,166 3/1963 Great Britain ..226/170 Primary Examiner-John M. Horan Assistant Examiner-Alan A. Mathews Attorney-John W. Adams [57] ABSTRACT This disclosure relates to a method and apparatus for processing photographic prints which embodies a mechanism for quickly and easily varying the time of submersion of the paper in the individual developer solution tanks and which permits substantially uniform tensioning of the paper by providing means for automatically adjusting the drive friction between the paper and the driving rollers.

2 Claims, 7 Drawing Figures METHOD AND APPARATUS FOR PROCESSING PHOTOGRAPHIC PRINTS It is an object of the present invention to provide a method and apparatus particularly designed to transport strips of photographic print paper through a series of processing tanks while balancing the drive friction between the respective driving rollers and facilitating adjustment of the time the paper is submerged in each of the respective processing solutions.

It is a specific object to provide a transport belt or web for guiding photographic printing paper through a series of processing tanks while permitting quick and easy adjustment of the individual guide path for the printing paper through the tanks to controllably vary the submerged time of the paper in the individual tanks.

It is another specific object to provide a method and apparatus for maintaining the desired driving friction between the individual driving rollers and the photographic paper being processed in order to produce a substantially constant speed of travel in said paper as it is transported through the respective tanks.

These and other objects and advantages of this invention will be apparent from the following description made in connection with the accompanying drawing wherein like reference characters refer to similar parts throughout the several views, and in which:

FIG. 1 is a vertical sectional view taken substantially along the line 1-1 of FIG. 2 but showing a four tank assembly instead of the fragmentary portion thereof shown in FIG. 2;

FIG. 2 is a fragmentary top plan view of the unit shown in FIG. 1 with the paper removed;

FIG. 3 is a vertical sectional view taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a fragmentary vertical sectional view taken substantially along the line 44 of FIG. 2;

FIG. 5 is an enlarged fragmentary sectional view taken substantially along the line 55 of FIG. 2;

FIG. 6 is a fragmentary sectional view taken substantially along the line 6-6 of FIG. 5; and

FIG. 7 is an enlarged fragmentary elevational view of a typical roller transport assembly with the belt broken away.

FIG. 1 shows a series of processing tanks 10, 11, I2 and 13 mounted on a suitable base structure 14, the upstanding side walls of the tanks have rollers l5, l6, 17, 18 and 19 respectively mounted thereon. Guiding and stabilizing rollers 20, 21, 22 and 23 are mounted in the lower portions of the respective tanks 10, ll, 12 and 13. The rollers 20-23 are vertically adjustable by any suitable means such as the notched plastic support plates 24 having said stabilizing rollers respectively mounted at the lower ends thereof. Each of the plates 24 may be twisted to disengage the notches in the plates from the anchoring rods 25 and the roller and plate assembly may then be vertically adjusted and the rods 25 re-engaged with selected notches to position each roller at the desired elevation within its tank.

A transport belt 26 for initially guiding the paper through the tanks is trained over the upper rollers -19 and under the stabilizing lower rollers -23 in slightly spaced relation below said lower rollers as best shown in FIG. 1. A supply of exposed printing paper 27 in the form of a roll 27a is mounted on a shaft 28 which is journalled on suitable mounting brackets 29 and the paper 27 is guided around the respective rollers 15-19 and 20-23 by the transport belt 26.

From the upper roller 19 the paper 27 and belt 26 pass into a conventional drying chamber (not shown) from which the paper is discharged onto a suitable takeup roller (not shown). The transport web passes down under the drying and processing tanks and around an idler roller 30 as best shown in FIG. 1 and up around a roller assembly for maintaining the desired tension therein and to accomodate variations in length due to adjustments in the length of the respective festoons in the tanks 10-13. This tensioning roller assembly in the form shown consists in a weighted roller 31 mounted in a pair of guiding slots 32 formed in the end plates of the housing and idler rollers 33 are provided to guide the web 26 onto the tensioning roller 31. The guiding roller 34 is also provided for guiding the belt 26 under the paper 27 as best shown in FIG. 1.

Each of the upper rollers 15-19 is driven by a suitable power source (not shown) which drives a common drive shaft 35 at a uniform constant speed. A plurality of worm gears 36 are connected to the shaft and respectively drive pinions 37 which in turn are respectively mounted at the ends of the rollers 15-19 which are all driven at the same uniform speed. The roller 16 illustrated in FIG. 4 is typical of the upper rollers 15- 19. Each of said rollers has a plurality of equally spaced beltengaging cog elements 38 mounted at the center portion thereof adapted to mesh with the center perforations 26a of the belt 26. The belt 26 is retained in meshed relation around each of the rollers 15-19 by a pair of retaining flanges 39 having spaced access notches 39a formed in the edges thereof to permit the belt 26 to pass under the flange portions, around the roller and out from under the flange portions on the other side of the roller as best shown in FIGS. 5, 6, and 7. A locking detent 39b is provided for engaging the upper ends of the tanks to prevent rotation of the flanges 39. A pair of paper driving rings 40 are mounted around each of the rollers 15-19 and provide a slightly larger diameter for the rollers so that the periphery of said rings engage the back side of the paper web as it passes therearound thus preventing contact between the paper and the cogs and eliminating the possibility of damage to the paper by contact with the relatively sharp cogs 38.

A suitable clip (not shown) may be provided to connect the leading end of the paper to the belt 26 in order to facilitate threading the paper through the developer tanks and drying chamber and onto the takeup roller (not shown). When the paper has been threaded through the developer tanks the same is driven by contact with the enlarged driving rings 40 of the rollers 15-19. The diameter of the paper driving rings 40 is larger than the diameter of the cogged portion of each of the rollers l5-l9 as described above. This larger diameter of the rings produces an over drive effect on the paper relative to the speed of the web 26. This requires controlled slippage between the paper and the rings 40. This controlled slippage is produced by the detainer plates 41 mounted opposite each of the driving rollers 15-19 as best shown in FIG. 1. The frictional engagement between the surface of the paper and the rings 40 is limited by detainer plates 41. The detainer plates 41 cause the paper to loop slightly ahead of the respectively adjacent rollers and thus reduce the driving friction between the roller rings and the paper surface. This produces more slippage as contact with the plate and the frictional drag produced thereby is increased. This reduces the frictional driving contact between the paper and the rollers 15-18. As the festoon extending downwardly into the tank is slowed down by the drag of the detainer plate, this produces tension in the paper which will increase the frictional driving force exerted by the next roller ahead of that detainer plate and the paper by pulling down on the loop will tend to remove the looped paper from that detainer plate 41 and thus reduce the frictional drag produced by that plate. By controlling the driving friction between the paper and the rollers 15-18 a substantially constant transport speed is achieved which produces substantially the same speed as the belt 26. This also automatically compensates for variations in the paper length produced by expansion or contraction of the paper when in contact with the processing solutions in the tanks.

It will be seen that I have provided a highly efficient method and apparatus by which the length of submerged time of photographic print paper in a series of different processing solutions can be individually controlled including the provision of method and apparatus for maintaining a substantially constant transport speed on the paper as it travels through the various solutions.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportion of the parts without departing from the scope of the invention, which generally stated, consists in the matter set forth in the accompanying claims.

What is claimed is: v 1 Apparatus for processing photographic prints comprising a plurality of separate and individual solution tanks,

an endless transport belt mounted in festooned relation in said tanks with at least one depending festoon extending downwardly into each tank,

means for driving said belt to move the same in a predetermined guide path progressively through the respective tanks,

a plurality of belt engaging rollers respectively mounted in the upper portions of said tanks,

said belt and said rollers having cooperative interfitting means to positively determine the length of the respective festoons in the tanks,

said interfitting means being readily disengageable to permit the length of the festoon in each tank to be adjustably varied,

a guiding roller mounted in the lower portion of each of the tanks to stabilize the festoons as the belt passes through the tanks in the selected predetermined guide path, means for vertically adjusting said rollers with means for positively positioning the same in accordance with the length of the festoon in each tank, and each belt engaging roller having a plurality of peripherally spaced cogs connected therewith and said belt having similarly spaced openings to respectively receive said roller cogs, a pair of retainer flanges releasably overlying the marginal edge portions of the belt when the same is meshed with said cogs to releasably retain the interfitting relationship between the belt and the cogs.

2. Apparatus for processing photographic prints comprising a plurality of separate and individual solution tanks,

means for initially transporting the leading end of a supply of photographic print paper in a predetermined guide path through said respective tanks,

a plurality of paper driving rollers respectively provided for said tanks and having frictional driving engagement with said print paper to move the same progressively through the tanks in the predetermined guide path,

a paper detainer plate disposed in slightly spaced opposed relation to each of said driving rollers for engaging the paper when the adjacent roller is moving the paper faster than the next successive roller, and

the frictional resistance between the paper and detainer plate producing a loop in the paper to reduce the driving friction of the adjacent roller and reduce the speed at which the paper is being driven to thus stabilize the speed of travel of the paper through the tanks. 

1. Apparatus for processing photographic prints comprising a plurality of separate and individual solution tanks, an endless transport belt mounted in festooned relation in said tanks with at least one depending festoon extending downwardly into each tank, means for driving said belt to move the same in a predetermined guide path progressively through the respective tanks, a plurality of belt engaging rollers respectively mounted in the upper portions of said tanks, said belt and said rollers having cooperative interfitting means to positively determine the length of the respective festoons in the tanks, said interfitting means being readily disengageable to permit the length of the festoon in each tank to be adjustably varied, a guiding roller mounted in the lower portion of each of the tanks to stabilize the festoons as the belt passes through the tanks in the selected predetermined guide path, means for vertically adjusting said rollers with means for positively positioning the same in accordance with the length of the festoon in each tank, and each belt engaging roller having a plurality of peripherally spaced cogs connected therewith and said belt having similarly spaced openings to respectively receive said roller cogs, a pair of retainer flanges releasably overlying the marginal edge portions of the belt when the same is meshed with said cogs to releasably retain the interfitting relationship between the belt and the cogs.
 2. Apparatus for processing photographic prints comprising a plurality of separate and individual solution tanks, means for initially transporting the leading end of a supply of photographic print paper in a predetermined guide path through said respective tanks, a plurality of paper driving rollers respectively provided for said tanks and having frictional driving engagement with said print paper to move the same progressively through the tanks in the predetermined guide path, a paper detainer plate disposed in slightly spaced opposed relation to each of said driving rollers for engaging the paper when the adjacent roller is moving the paper faster than the next successive roller, and the frictional resistance between the paper and detainer plate pRoducing a loop in the paper to reduce the driving friction of the adjacent roller and reduce the speed at which the paper is being driven to thus stabilize the speed of travel of the paper through the tanks. 